3 secrets to making your relationship last

The INSIDER Summary:

"One star, one rock" is the idea that outgoing people match well with more reserved personalities.

Communication is important, but don't talk a relationship to death.

Finding love is no easy task, but helping other people meet that special someone can be even harder. Today's "modern matchmakers" have a lot to consider when setting people up in the hope of sparking connections that last.

There are, however, a few tricks of the trade.

INSIDER asked professional matchmakers what they think the secrets to lasting, fulfilling relationships are. Here's what they had to say.

"Chemistry is the cement that keeps it together."

Physical affection changes your brain chemistry. Shutterstock

"Life is a lot of ups and downs and in betweens," said matchmaker Chana Rose. "Chemistry is the cement that keeps it together. It's not something you have to define, but it definitely has to be there ... The chemistry factor is crucial."

It's not just Rose's 30 years of experience in the field that back this up — science does, too.

A study published in the Journal of Social Psychological and Personality Science found that when couples reported being "very intensely in love," physically affectionate behavior was the top factor, even more so than the frequency of sex. Acts like hugging and kissing release oxytocin, which is sometimes called the "love hormone" because it promotes feelings of closeness and bonding.

"One star, one rock."

When it comes to long-term compatibility, matchmaker Talia Goldstein focuses on how personalities fit together.

The founder of Three Day Rule abides by a rule of her own, which she calls "one star, one rock." This means that in a relationship, one person is more vivacious and outgoing, while the other is more supportive and introverted.

People with big personalities often look for someone similar to them in that way, but Goldstein says that, that dynamic isn't usually successful.

"They have these very vivacious personalities, they're sort of the life of the party, and they want somebody just like them, but we find that, that doesn't work very well," she said of the "stars." "Typically, their best match is a confident, more introverted type that adores them and is there supporting them."

The founder of Tawkify told INSIDER that while conversation can be an important way to make sure you're in tune with your partner, some things are best left unspoken.

"Stop yammering," she said. "There's too much. This talking over every little thing is killing the fun. Shut up, be quiet, just enjoy one another. Oh my god, no wonder people break up left and right, they just talk the thing to death."

For more insights from these matchmakers, and to read more about why the old-school practice is making a comeback in today's dating world, click here.